Method and apparatus for making hollow



Aug; 9, 1960 Re. 24,860

C. KYLE METHOD AND APPARATUS FOR MAKING HOLLOW ACCRETED FIBROUS BODIES Original Filed May 2. 1952 3 Sheets-Sheet 1 "IIIIIIA Y INVENTOR.' QQLIN KYLE Aug. 9, 1960 C. KYLE Re. 24,860

METHOD ANO APPARATUS FOR MAKING HOLLOW AOORETEO FIBROUS BOOIs 3 Sheets-Sheet 3 Original Filed May 2. 1952 FIGB - JNVENTOR.' .U N K-YLE BY Mnl.

Lk vf ATT'YS United States Patent lOiice Re. 24,860 Reissued Aug. 9, 1960 METHOD AND APPARATUS FOR MAKING HOLLOW ACCRETED FIBROUS BODIES Colin Kyle, Geneva, Ill., assignor to Hawley Products Company, St. Charles, Ill., a corporation of Delaware Original No. 2,723,600, dated Nov. 15, 1955, Ser. No; 285,831, May 2, 1952. Application for reissue Nov. 15, 1957, Ser. No. 697,302

11 Claims. (Cl. 162-219) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specilication; matter printed in italics indicates the additions made by reissue.

-This invention relates to a method and apparatus for making hollow accreted fibrous bodies, more particularly unitary hollow contoured bodies and especially hollow bodies where the clearance between opposite walls or sides of the hollow body is relatively small.

Hollow bodies of the vtype contemplated by the invenvention are especially useful as packaging elements for watches, instruments, and other delicate devices which are readily damaged in shipment and require special precautions to prevent such damage. Attempts to make such hollow bodies by injecting pulp mixtures into a mold have been made but the distribution of the pulp is generally non-uniform, with the result that weakened places develop particularly at or near the juncture of opposing walls separated by a relatively narrow space.

One of the objects of the present invention is to provide a new and improved method for making hollow bodies.

Another object of the invention is to provide a new and improved method for making hollow bodies from brous materials by accretion onto a foraminous mold.

Still a further object of the invention is to provide a new and improved method for making hollow bodies in which some of the walls are spaced from each other only a limited distance.

An additional object of the invention is to provide a new `and improved apparatus for making hollow bodies of the type described.

Other objects and advantages of the invention will be apparent by reference to the following description in conjunction withn the accompanying drawings in which:

Figure l represents a cross sectional View of a hollow body that can be manufactured in accordance with the invention;

Figure 2 is a plan view of the hollow body shown in g Figure l;

Figure 3 illustrates in section an elevational view of an apparatus which can be used in the practice of the invention and also illustrates the first step in carrying out the method;

Figure 4 shows the apparatus of Figure 2 in the position occupied by the elements thereof in carrying out the .second step of the method;

Figure 5 illustrates the position of the elements of the :apparatus in carrying out the third step of the method;

Figure 6 is a cross sectional view lof the apparatus shown in Figure 5;

Figure 7 illustrates a variation of the arrangement of the parts of the apparatus shown in Figure 5;

Figure 8 is a cross sectional view of the apparatus shown in Figure 7; and

Figure 9 illustrates the knitting of the edges of the holjlow body member during the operation of the process in the step carried out in Figure 4.

In accordance with the invention a hollow body is formed by first accreting at least two separate components of the hollow body in an aqueous bath containing fibers of the material which are to be accreted in forming said body, then without removing the accreted component parts from the bath, bringing said parts together and con tinuing the accreting Operation until the bers become knitted at the junctures of said component parts. In this manner a unitary hollow body is formed, with the junctures of the component parts being completely sealed. The hollow body is then removed from the bath and dried in any suitable manner by introducing heated air into the interior of the hollow body through a suitable opening and subjecting opposite sides of the hollow body to suction to cause the heated air to be drawn through the walls of the hollow body.

In the drawings the hollow body 'is illustrated as a packaging unit which can be used, for example, as a wristwatch case. It will be understood, however, that the invention can be used in manufacturing various other types of hollow bodies and especially those which are suitable for use as packaging units. AIn this connection it will be noted that the walls 1 and 2 in the hollow body illustrated in Figure l are rather close together at the point 3. When it is attempted to manufacture a piece of this kind by injecting a prulp mixture into a suitable foraminous mold and withdrawing water through the openings in the mold the rush of water through the narrow passageway illustrated by the numeral 3 causes the ibers to be washed away at this point with the result that the structure of the hollow body thus produced is relatively weak and non-uniform.

For the practice of the present invention at least two component parts of the hollow body member are separately formed in a felting bath. As illustrated in Figure 3 the felting bath 4 is held in a suitable container or tank 5. The felting bath can consist of a mixture of bers in a liquid, for example, cellulose libers in water with or without the addition of resins or other materials that may be added for a specific purpose.

ln the embodiment of the invention illustrated in Figure 3 two dies 6 and 7 are provided to form two component parts of the hollow body. The die 6 which in the embodiment illustrated is located near the bottom of the tank 5 is provided with a contoured surface 8 generally corresponding to the shape of one of the walls of the hollow body member and provided with holes or apertures 9 over which is placed a foraminous screen 10 having a large number of relatively line Openings. An outlet 11 is connected to a suitable source of vacuum, not shown, by means of which suction can be exerted on the interior 12 of the die 6 thereby causing the fibers from the felting bath 4 to be deposited on the screen 10. These fibers when built up to a suitable thickness form the component wall 1 of the hollow body.

-The die 7 is similar to the die 6 except that it is a male rather than a female die. The portion 13 of the die 7 generally conforms to the shape of one of the walls of the hollow body which is to be formed and is provided with apertures 14 over which is placed a foraminous screen 15 similar to the screen 10. The outlet 16 is connected to a suitable source of vacuum, no-t shown, to create suction in the space 17 thereby causing the fibers in the bath 4 to be deposited on the screen 15. When these iibers build rup to the desired thickness the wall 2 of the hollow body is formed.

It should be noted that the dies 6 and 7 are relatively movable one with respect to the other in an axial direction so that they can be brought together beneath the surface of the bath and thereafter both dies, carrying the hollow body between them, can be moved out of the bath. Any suitable mechanism can be provided for moving the dies, the type of mechanism employed being immaterial from the vstandpoint of this invention. 'If desired the dies can be moved by hand. A suitable seal 18 is provided around the outlet pipe 11 to prevent the escape of liquid fromvthe bath.

Infthe structure-shownin Figure 3. thedie -6 is separable atthe point 19 and the-upper or foraminousportioni can be removed from'the bath ytogether with the hollow body that is formed-when the upper .and-lower dies are brought together. In 'the embodiment shown a tubular member 20extends ythrough thelower side of vthe.-die 6 andY also through the aperture portion -8 andthe screen( 10 and projects above the wall 1 ofthe hollow body that is formed on the screen 10. fThe purpose of the tube 20is to form an opening inthe wall 1 of the hollowbody in'order to allow the lluids of the bath to enter .the interior cavity-of V-the hollow bodyafter'the dies `6 and k7 lhave been brought to- 'geth'er and to facilitate drying ofthe hollow bodyqafter the latter has been formed and in the manner hereinafter described. As shown in Figure 6 `it isfpreferable to pro vide two tubes 20 and 21 to forma pair of openings-in the hollow =body.

When the-walls 1 and 2 have been formed to the desired thickness by the'accretionfor deposition of fibers on the screens Illand respectively of the dies 6- and 7 the die 7 is moved downwardly `as shownin Figure 4.

It will be noted that the component parts land 2 of the hollow body are Iformed with anges 22 and 23, respectively, V which extendraround the margins or edges of 'these component parts.

After fibers have been Vaccreted `to the desiredthickness informing the component parts or walls 1 and 2 the die 7 is moved axially until the llange portions 22 and 23 unite as shown in `Figurev 4 to formr a unitary flange 24. Itis essential for the purpose of the invention that this uniting of the accreted components take place as a part of the accreting `process and without removing these components from theV bath. The reason for this can beiexplained with reference to Figure 9 wherein it will be seen that the individual fibers of the -article 'tendto extend outwardly from the vface of the component parts 1y and 2 and unite Witheach-other when the anges 22 and 23 are brought together in the wet. However, if these fibers are removed from thefbath` they become flattened againsty the side of the `flange and do not `interlaceand'cornbine n the Aproper manner.

When the separately formed accreted wall -portions are ybrought together and united at the anges the yexertion of suction through the lines 11 and 16 in Figure 4 is continued and thereis a substantial build-up of fibrousmaterial at the point 25 thereby further strengthening'v the bond between the component parts land 2. This build-.upvis made possible by -thefact that the pipes or tubes and 21 extend' into the interior 'of the yhollow. bodyandfpermit circulation of the'tibenliquid bath to fthespace `26 after the component Vparts 1 and 2 have beenl united pbyfthey Vyflange 24.

In a relatively short time after the-component parts Y1 andy 2 'have been :united the ybond between these :parts is 'sufficiently strong to permit removal of the hollow body 'from the bath. This removaly can be accomplished fin several ways, ffor' example kas previously yexplained ybyreniov- `ing the aperture-portion 8of 'the die `6which is separable from the die 6 at the point V19. rHence the aperture-porztion 8 can be moved upwardlytogether with thedie 7 and withy the hollow body between them. Alternativelytvthe entire die structures 6 and 7\can vbe moved axially out of vthe bath. Regardless'rof'whether both diesare vremoved from the bath or whether lthe upperdie1 is `removed. together with the hollow'body memberland thescreenportion vof Vthe lower die, the nextfstep is to dry the hollow vbody vmember and this is preferably accomplished finlt'he manner illustrated :in Figure 5.

shown in Figures 5 andothe hollow body-member :carried betweenitwoffforalninous t dieslfis fdri'ed *"by"I introzducingahot fairithreughzthe tubes-fontana y(121"lintoithefeentral lspace 26 of the hollow body..memberandsimultaneously applying suction through the pipes 16 and 17 to cause the heated air to be pulled outwardly from the interior spce 26 through the walls 1 and 2. In this way the moisture which still remainsfrom the accreting bath is rapidly removed and 4thehollow articleis driedto-.the desired moisture. content. The dies are then .separated and the hollow' article is removed.

Figures 7zand'i 8 illustratean alternatieve'y embodimentuf the f invention .in y:which theihollow :article isremovedfrom the dies 6 and 7 before beingdried. between a pairoftdry- 1ngdes-27 and 28. The `general method.oftdryingohowevex ,`1s essentially the same-'Heated air is-introducedtinto the interior 26 of the hollow article through pipes 29 and 30. Suction is applied through fpipes'- 31Uand 32 thereby drawing the heated air from the interior of the hollow article through thewallsand removing themoistureladen air.

x llt-will be Y recognized :that a` `.large number'of hollow articles may be made simultaneously from vtheI sameA l:felting bath. The invention is not limited to the employment of'- any particulartypeV of fiber for forming "the hollow article. l'EXam'pleso-'suitable fibers are kraft, sisal; hencquen, :caroa (BraZiIianpineapple)," 'glass fibers and .mixtures of such fibers.

The invention lmakes it possible to produce stronger hollow'fber articles having *closely spaced side walls at one ormore points ythan can beobtained 'by injecting a liber-liquid mixture into a yunitary mold or form. The inventionalso Aavoids thin, non-uniform distribution o the 'iberswhichoccurs when such articles 'are madeby the injectionmethod.

'Inthe-.type of rhollow article illustrated in" the drawings the lianges which are provided-for uniting the two `compolnentl parts 4of the article vca11,`if desired, beremoved mechanically, for example by sawing orpunching. "The component parts ofthe article can also beknitted together by internalffianges or without-substantial anged portions.

Instead fof `two-complemental component parts *the article may -beformed from threeormore complemental component partsusing a=corresponding number of dies. 'The method .of formingthe `ar-ticle with an lexternal ange represents `a preferredembodimentfof'the invention. l

fIt `will be understoodthat the 0size and' contoursgof articles formed in the practice of the inventionmay vary ,widely/1': depending upon the purpose-for which-the article 1s use The invention is hereby claimed as follows:

1. A lmethod of making' fibrous hollow `articles -which `comprises accreting fibrousy separatev component parts of a hollow .bod-y -in ypredetermined shapes from ya fiber-liquid -bath',.said .parts defining a substantially enclosed hollow spacerbetween themr when brought together, bringing said accreted component parts together without removingthem Vfromfsaid'bath, and thereafter continuing 'tof accretelibers on the inner surfaces of the resultant hollow article until said vpartsare: securely zunited.

x 2. Asmethod fofsmaking'ibrous hollow articleswhich comprises. accreting fibrous lseparate component parts rof a hollow body in predetermined shapes from a'liber-liquid bath, fsaid'- yparts defining af'substantially enclosedfhollow spacexbetween'them when brought together', saidecomponent parts each having a langecomplementalone with the -other, bringing said .flanges -of -said accreted .zcom- ,ponent aparts together without removing -them fromfs'a'd bath, 'and thereafter` continuing to accreteiibers -on'the inner surfaces of the resultant hollow articlel until 'Said :partsfaresecurely united.

3. A method of making fibrous hollow 'articles vwhich comprises laccreting two fibrous, component partsfof a hollow body in predetermined shapesf from Va ben-liquid bath', :saidf parts defining a substantially l'e1'1closetlhollow Vspacebetweenfthernwhen brought togethen'feachbf said component parts being provided Withangesthat are complementalone'witlitthetother, bringing'saidfllanges of from said bath, thereafter continuing to accrete fibers on l the inner surfaces of the resultant hollow article until said parts are securely united, and during said last named accretion introducing a portion of the fiber-liquid mixture into the hollow body of the article.

5. A method of making fibrous articles which comprises accreting iibrous separate component parts of a hollow body in predetermined shapes from a fiber-liquid bath, said parts defining a substantially enclosed hollow space between them when brought together, bringing said accreted component parts together without remo-ving them from said bath, thereafter continuing to accrete bers on the inner surfaces of the resultant hollow article until said component parts are securely united, removing the resultant article from the ber-liquid mixture, and introducing a heated fluid into said hollow body of said article.

6. A method of making ibrous articles which comprises accreting iibrous separate component parts of a hollow body in predetermined shapes from a fiber-liquid bath, said parts deiining a substantially enclosed hollow space between them when brought together, bringing said accreted component parts together without removing them from said bath, thereafter continuing to accrete bers on the inner surfaces of the resultant hollow article until said component parts are securely united, removing the resultant article from the ber-liquid mixture, and introducing a heated iluid into said hollow body of said article while applying reduced pressure to the exterior of said article.

7. An apparatus for making hollow brous articles comprising means to contain a ber-liquid bath, separate forming dies each adapted to be submerged in said bath and to form by accretion a complemental component part of a ibrous contoured hollow article, said parts defining a substantially enclosed hollow space between them when brought together, means to move said dies one with respect to the other to bring them in juxtaposition in said bath with said parts adjoining and defining said hollow space, and means to introduce a portion of said bath between said dies and into said hollow 'space when said dies are brought into said juxtaposition.

8. An apparatus for making hollow fibrous articles comprising means to contain a ber-liquid bath, separate forming dies each adapted to be submerged in said bath and to form by accretion a complemental component part of a brous contoured hollow article, said parts defining a substantially enclosed hollow space between them when brought together, means to move said dies one with respect to the other to bring them in juxtaposition in said bath with said parts adjoining and defining said hollow space, means to introduce a portion of said bath between said dies and into said hollow space when said dies are brought into said juxtaposition, and means for applying suction within said dies communicating with the surfaces of said dies to cause iibers to be deposited thereon from said liber-liquid bath.

9. An apparatus for making contoured hollow brous articles comprising a container for a fiber-liquid mixture, a foraminous female forming die contoured to the `general shape of one part of the article to be formed and adapted to be immersed in said fiber-liquid mixture, a foraminous male forming die contoured to the general shape of another part of said article to be formed and' adapted to be immersed in said fiber-liquid mixture, said parts defining a substantially enclosed hollow space between them when vbrought together, said dies being movable one with respect to the other to permit them to be separated' and brought together with said parts adjoining and defining said hollow space, and being provided with foraminous flanges extending around terminal edges of said dies and adapted to hold the flanges of a hollow article between them when said dies are brought together, means to move said dies relative to each other to bring them together in said mixture in said container a plurality of tubes extending entirely'through at least one of said dies to permit introduction of the fiber-liquid mixture between said dies and into said hollow space when they are brought together, and means for providing a reduced pressure space in the interior of each said dies, said reduced pressure space communicating with the foraminous portions of said dies including said iianged portion.

10. A method of making a jbrous article havnga cavity which comprises accreting from a fiber-liquid bath fibrous separate component parts each having an extended accreted marginal open edge portion on dies at least one 0f which is a female die, which parts when brought logether at said edge portions form an article having a cavity, bringing said edge portions together without removing said parts from said bath, and thereafter continung to accrete ybers whereby said parts are securely united.

11. An apparatus for making a fibrous article having a lcavity which comprises means to contain a fiber-liquid bath, separate forming dies each adapted to be submerged in said bath and to form by accretion a complemental component part, each of said dies having a porous edge portion for forming a marginal open edge portion on said component part which when brought together form an article having a cavity, means to move said dies with respect to the other to bring them in juxtaposition in said bath with said edge portions in proximity to each other, means operative to supply a fiber-liquid slurry in proximity to said edge portions, and means applying suction to at least said porous edge portions to cause said bers to be accreted in intimate association with the joint between said edge portion.

References Cited in the le of this patent or the origlnal patent UNITED STATES PATENTS 549,998 Fairbanks et al. Nov.19, 1895 1,342,184 Rauer June 1, 1920 1,367,096 Rivers Feb. 1, 1921 1,690,528 Bushnell Nov. 6, 1928 1,873,585 Harvey Aug. 23, 1932 1,875,075 Mason Aug. 30, 1932 2,257,573 Randall Sept. 30, 1941 FOREIGN PATENTS 304,442 Germany Oct. 28, 1915 133,952 Great Britain Apr. 13, 1921 

